The present invention relates to a gas turbine combustor, more particularly, to a gas turbine combustor having air flow rate control means which enables an improvement of the reliability of the combustor.
In, for example, Japanese Patent Laid Open Application No. 168821/1983, a low NOx combustor for a gas turbine is proposed having a regulation ring which is slidable in a circumferential direction of an inner cylinder of the combustor for controlling a primary air flow rate and a secondary air flow rate introduced into the inner cylinder in accordance with variations of the load to reduce concentrations of nitrogen oxides; however, a disadvantage of this proposed construction resides in the fact that the air flow rate regulation ring has a mechanical sliding part contacting an outer surface of the inner cylinder, and repetitive sliding operation wears out the regulation ring thereby making it difficult to exactly control the air flow rate in the inner cylinder.
A further disadvantage resides in the fact that the wear phenomenon on the regulation ring may result in premature formation of cracks therein, whereby a portion or part of the member of the regulation ring is broken or severed into small pieces or fragments which ultimately may be drawn or blown into the turbine connected to the downstream side of the combustor, thereby resulting in serious damage to the moving blade and stationary blades of the turbine.
The aim underlying the present invention essentially resides in providing a gas turbine combustor with an air flow rate control means, wherein an arrangement is provided for enabling an accurate control of the air flow rate entering a combustor and for providing an improved long term reliable operation of a gas turbine.
In accordance with advantageous features of the present invention, an air flow rate control arrangement is provided for properly maintaining the relationship between the combustor and movable parts thereof in a non-contacting manner thereby increasing the overall lifetime of the gas turbine.
In accordance with the present invention, a gas turbine combustor is provided which includes an inner cylinder forming a combustion chamber therein and a plurality of air supply ports in a circumferential wall member as well as a fuel nozzle. An outer cylinder forms a cylindrical air passage between the outer surface of the inner cylinder and the inner surface thereof, and a control means, having a flexible member, is provided for support thereof and is adapted to regulate the air flow rate supplied through the air supply ports when the gas turbine is operational.
By virtue of the features of the present invention, it is possible to improve the reliability of the gas turbine combustor with respect to a long-term operation of the gas turbine and to reduce the concentration of NO.sub.x throughout the entire load range of the gas turbine.